$D_s$ decays to $\eta$ and ${\eta }^{\mathrm{\prime }}$ final states: a phenomenological analysis

We consider the semileptonic and nonleptonic $D_s$ decay modes to final states with $\eta$ and ${\eta }^{\mathrm{\prime }}$. We use QCD sum rules to determine the $D_s\to \eta$ form factor $f_{+}^{\eta }$, and a generalized factorization ansatz to compute nonleptonic decays. We propose a parameterization of possible OZI suppressed contributions producing the ${\eta }^{\mathrm{\prime }}$ in the final state, compatible with current data; such a scheme can be further constrained improving the precision of the measurement of the $D_s$ decay rates, as expected by the ongoing experiments.